12019 is a porphyritic basalt with high proportion of pigeonite phenocrysts and a few vesicles. In places its outer surface is pock marked with micrometeorite craters. It has not been dated. 12019 has a variolitic texture with abundant small pyroxene phenocrysts set in a fine-grained groundmass. It is unusual in that it has many small pyroxene phenocrysts instead of a few large ones. Groundmass includes small (0.6-0.05 mm) laths of plagioclase, pyroxene, ilmenite with minute anhedral ulvöspinel, troilite and metallic iron (containing Ni and Co).
The sample weighed 462.4 grams before analysis.
Deterioration of the mounting resin over time has produced a crystal-rich margin to this sample.
Further details of this and other Apollo samples are here: http://curator.jsc.nasa.gov/lunar/
Apollo 12 returned 34 kilograms of samples, including 45 rocks, samples of lunar 'soil', and several core tubes that included material from as much as 40 centimetres below the lunar surface.
Apollo 12 rocks were almost all basalts, with only two breccias in the returned samples. The basalts at the Apollo 12 site formed 3.1 to 3.3 billion years ago, roughly 500 million years later than the Apollo 11 basalts. Overall, there is much less of the element titanium in the Apollo 12 samples than in the Apollo 11 samples, which explains the more reddish colour of this region. The differences in age and chemical composition between the Apollo 11 and Apollo 12 samples demonstrate that mare volcanism did not occur as a single, Moon-wide melting event.
Apollo 12 was launched on 14 November 1969.